This invention relates to the field of instruments for positioning a portion of the body for a medical procedure.
The flexibility of the human jaw is due to the structure of the temporomandibular joints (TMJ). The condyles of the mandible meet with the temporal regions of the skull to form what are strictly speaking the temporomandibular articulations. Each articulation actually is formed from two joints The first joint occurs between a condyle and interarticular fibro-cartilage. The second joint occurs between the fibro-cartilage and the glenoid cavity of a temporal region of the skull. This double joint arrangement allows the jaw extensive movement.
The temporomandibular joints are susceptible to a variety of disease states and injuries. Many of these problems are correctable by surgical intervention; however, before performing surgery on the temporomandibular joint, it is desirable for the surgeon to view the joint. By visualizing the TMJ, the physician can determine if surgical intervention is indicated. Typically the temporomandibular joint is visualized arthoscopically using an endoscope with a video camera. In order to visualize the TMJ, the jaw must be manipulated, that is, for example, drawn downward and forward to create a space in the capsule of the temporomandibular joint to allow an endoscope or other instruments to be presented into the capsule.
To manipulate the jaw, the physician or assistant in one technique wraps his sterile gloved thumb with a sterile gauze and inserts his thumb in the patient's mouth to grip the patient's jaw between his thumb and fingers. This technique, however, exposes the thumb to the patient's teeth, thereby creating the risk of infection for the person manipulating the jaw. Additionally, since the thumb is of a finite thickness, the manipulation is unable to include the complete closing of the jaw and thereby precludes moving the jaw through the dynamic range of which the jaw is capable.
A second technique requires the gripping of the jaw with a towel clip. A towel clip is an instrument which resembles miniature ice tongs. The pincers of the tongs penetrate the skin and muscle of the patient's jaw, and the physician can then, by pulling on the handle, move the jaw as he wishes. In addition to the inherent pain, this procedure leaves the patient with two puncture holes.
The present invention provides an apparatus by which the surgeon, using only one hand, may manipulate the jaw of the patient into the correct position for arthoscopic examination of the full range of jaw motion without exposing the surgeon to infection and without injuring the patient.